Switchgear and Protection

Buchholz Relay Buchholz relay is a protective and gas actuated relay . It is used in that transformer whose winding is immersed in oil and rating having more than 500KVA. It is used to the transformer against internal or incipient faults only. Basically, it is used for detection of winding faults. Buchholz relay is invented […]

Vacuum Circuit Breakers (VCBs) Since vacuum offers highest insulating strength, so it can use as arc quenching medium. The circuit breakers that use vacuum as a arc quenching medium, known as vacuum circuit breakers (VCBs). Construction of Vacuum Circuit Breakers It consists of two contact one is fixed and other is movable and these contacts […]

Induction Type Over Current Relay Induction type over current relay works on the induction principle. This relay operates when current in the circuit exceeds the predetermined value. These relays are used on ac circuits only. Construction This relay has two electromagnets. Upper magnet Lower magnet The upper magnet has three limbs and primary and secondary […]

Valve type Lightning Arrester Valve type lightning arrester is extensively used on system operating at high voltage. It consists of two parts. Series spark gaps Non-linear resistor discs The non-linear resistor is connected in series with the spark air gap. Both the assemblies are accommodated in tight porcelain container. It is also known as non-linear […]

Reactors The electrical energy or electricity has become a part and parcel of our life. Electricity plays an important role of our daily’s life. The demand of electrical energy is increasing day by day. To meet this demand, the power system expands and become more complex. In this way fault level is also increased. To […]

Electrical Faults in Overhead Transmission Lines The occurrence of faults in overhead transmission line is common thing. In this article, we will discuss about, electrical faults in overhead transmission lines, types of electrical faults and reasons of electrical faults. What is an electrical Fault? An electrical fault is any defect in the electrical circuit due […]

Horn Gap Lightning Arrester Horn gap lightning arrester was the earliest types of lightning arrester. It is consisting of two metal rods in the shape of horn and separated by a small air gap. It is connected in shunt between each conductor and earth. The distance between two rods depends upon the supply voltage. The […]

Rod Gap Lightning Arrester Rod Gap lightning arrester is the simplest form of Lightning Arrester. It is consisting of two (1.5cm) rods which are bent almost at right angles and placed across the transformer bushing or across the string of suspension type insulator in overhead transmission system. One rod is connected to the line circuit […]